A variety of paperboard containers have been developed in order to contain as well as display the contents placed therein. Additionally, a variety of containers having gusseted side walls which allow the side walls to be collapsed inward such that the front and back of the carton converges toward one another from a bottom of the carton to the top of the carton have also been developed.
One such similar carton construction is illustrated in U.S. Pat. No. 2,379,665. Therein, a carton having upper and lower gusset forming sections in each side wall is disclosed such that the front and rear panels of the carton will converge towards one another to form a handle in the upper portion of the carton. However, the gusset cannot be readily formed in the side walls without jeopardizing the overall structural integrity of the carton. That is, the carton may at any time be compressed and thus collapse along fold lines 21 and 26 during the erection of the carton. Moreover, the erection, filling and sealing of a carton in accordance with that disclosed in U.S. Pat. No. 2,379,665 may not be readily carried out by automatic machinery in that the side walls may buckle with the induced stress due to the buckling jeopardizing the structural integrity of the carton.
U.S. Pat. No. 4,243,171 issued to Prin discloses a similar carton construction for carrying articles. As with the above-mentioned carton, this carton includes two sets of gusset forming sections, one being in a lower portion of the side walls and another in an intermediate position along the length of the side wall. The gusset can thus be formed to extend along the entire length of the side wall or be formed intermediate the ends of the side walls. However, because the gusset forming system includes a plurality of prescored fold lines, the side walls may tend to buckle, that is, a portion of the side wall would fold outwardly rather than inwardly along the central fold line thus destroying the integrity of the side wall as well as the accurate formation of the carton. Moreover, the carton disclosed in U.S. Pat. No. 4,243,171 is intended for use as a bag shaped box or carrier for packing and carrying articles offered, for example, by shopkeepers to their clients to carry their purchases. Such a carton is not readily adaptable to automatic machinery for erecting, filling and closing the carton.
In an effort to provide a carton for manipulation by machinery for erecting, filling and sealing cartons, a carton was developed including front, back and side panels with the side panels including perforated cut score lines extending from a point substantially adjacent the fold line between the front panel and side panel and the back panel and side panel along the bottom of the side wall and converging towards one another to a center point at the top of the side wall. However, during the formation of the carton, the side walls often buckle and bow outwardly and the stresses induced by the buckling would thus induce reverse folding and even separation along the two perforated cut score lines which define the gussets in the side walls of the carton. When such occurs, the structural integrity of the carton is significantly impaired to the point where the carton is no longer useful in containing articles.
As can be seen from the foregoing, there is clearly a pressing need for a carton of the above-mentioned type which may be reliably formed and manipulated by machinery by forming, filling and sealing such cartons, without jeopardizing the structural integrity of the carton when formed. Additionally, there is a need for a carton which conveniently presents the goods placed therein in a manner which appeals to the consumer.